1. Field of the Invention
The present invention relates to an organic light emitting diode display device with enhanced reliability.
2. Discussion of the Related Art
Image display devices, which display a variety of information on a screen, are based on core information and communication technology and they are becoming increasingly thinner, lighter, more portable, and higher in performance. Thus, organic light emitting diode (OLED) display devices, which display an image by controlling light emission of an organic emission layer (EML), are flat panel display devices that may be designed to have lower weight and volume than with cathode ray tubes (CRTs).
Such OLED display devices include OLEDs, which are self-emissive devices using the EML, which can be a thin emission layer, between electrodes. An OLED may include a first electrode that is an anode connected to a thin film transistor (TFT) formed in each of sub-pixel regions of a substrate, the EML, and a second electrode that is a cathode.
In such OLEDs, when voltage is applied between the first electrode and the second electrode, holes and electrons are recombined in the EML, forming excitons, and the excitons drop to a ground state, whereby light is emitted. In addition, a passivation film is formed on OLEDs so as to cover the OLEDs and thus prevent permeation of moisture and oxygen into the OLEDs.
FIG. 1A is a plan view of an OLED display device according to related art.
As illustrated in FIG. 1A, the OLED display device according to related art includes a plurality of OLEDs formed in a display area of a substrate 10 and a pad part 20 formed in a non-display area of the substrate 10. In addition, the OLEDs are connected to the pad part 20 via wires 10a, and driving signals from the pad part 20 are applied to the OLEDs via the wires 10a. 
Such OLEDs are susceptible to moisture and oxygen and thus a passivation film is formed so as to cover the OLEDs. In this regard, the passivation film includes an organic film 13 to compensate for step differences due to foreign materials which permeate the display area. The organic film 13 is generally formed by coating and curing an organic insulating material. However, when coating the organic insulating material, the organic insulating material flows outside the display area along the wires 10a. 
FIG. 1B is an image showing defects of the OLED display device according to related art.
As illustrated in FIG. 1B, when the organic film 13 extends up to the outside of the display area of the OLED display device, external moisture and oxygen permeate into the OLEDs via the organic film 13. The moisture and oxygen permeating into the OLEDs react with organic EMLs of the OLEDs generating defects such as dark spots, whereby reliability of the OLED display device is deteriorated.